The integration mole drains as a low-cost drainage system with nitrogen fertilizers particularly ammonia gas to improve salt affected soils have a little attention. A field experiment was conducted at North Nile Delta , during the two summer seasons (2016 and 2017), to determine the impact of mole drains (mole drains in one direction and mole drains in two directions with open drainage) and nitrogen sources (urea, ammonium sulphate and ammonia gas injection) with gypsum addition (3ton fed.-1 for all plots) on improving some soil physio-chemical properties, rice productivity and N-uptake by plant as well as productivity of irrigation water (PIW), nitrogen application efficiency (NAE) and economic returns from rice production and water unit.

Results indicated that the application of mole drain along with open drainage seems to be favorable effective in reducing salinity and sodicity of the soil particularly in case of using two directions. The combination system of mole and open drainage resulted in a reduction of soil bulk density and soil penetration resistance, while increased the basic infiltration rate. Moreover, it had with ammonia gas injection a superiority in the increase of rice yield (ton/ fed.), N-uptake and nitrogen use efficiency compared with other treatments, accordingly this combination produced the important findings of such approach in improving salt affected soils and rice production. From the economic view, the optimum values of NAE, PIW, economic efficiency and net return from water unit for rice yield were achieved by using mole application with open drainage and ammonia gas injection